• Journal of KIISE:Software and Applications
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• v.32 no.7
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• pp.612-624
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• 2005

In this paper, we propose a surface-based registration using a gaussian weighted distance map for PET-CT brain image fusion. Our method is composed of three main steps: the extraction of feature points, the generation of gaussian weighted distance map, and the measure of similarities based on weight. First, we segment head using the inverse region growing and remove noise segmented with head using region growing-based labeling in PET and CT images, respectively. And then, we extract the feature points of the head using sharpening filter. Second, a gaussian weighted distance map is generated from the feature points in CT images. Thus it leads feature points to robustly converge on the optimal location in a large geometrical displacement. Third, weight-based cross-correlation searches for the optimal location using a gaussian weighted distance map of CT images corresponding to the feature points extracted from PET images. In our experiment, we generate software phantom dataset for evaluating accuracy and robustness of our method, and use clinical dataset for computation time and visual inspection. The accuracy test is performed by evaluating root-mean-square-error using arbitrary transformed software phantom dataset. The robustness test is evaluated whether weight-based cross-correlation achieves maximum at optimal location in software phantom dataset with a large geometrical displacement and noise. Experimental results showed that our method gives more accuracy and robust convergence than the conventional surface-based registration.

• The Korean Journal of Petroleum Geology
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• v.5 no.1_2 s.6
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• pp.1-8
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• 1997

Seismic stratigraphic analysis of the high resolution profiles obtained from the southeastern shelf of Korea divided the deposits into 4 sequences; 1) sequence D, 2) sequence C, 3) sequence B and 4) sequence A (Holocene sediments). Sequence D was deposited in shallow-water environment at west of the Yangsan Fault as the basin subsided. On the other hand, the eastern part was formed at the slope front. Landward part of the slope-front fill sediments were eroded and redeposited nearby slope due to the syndepositional tilting of the basin. This tilting probably resulted from the continuous closing of the Ulleung Basin. Sequence C is made of stacked successions of the lowstand fluvial sediments, transgressive sediments and marine highstand sediments derived from the paleo-river in the western part of the Yangsan Fault. Sequence C in the eastern part of the Yanshan Fault was formed at the shelf break. Progradation of the lowstand sediments resulted in broadening of the shelf. Sequence C in the eastern part was also tilted but the tilting was weaker than in Sequence D. During the formation of sequence B the tilting stopped and the point source instead of the line source started in both sides of the Yangsan Fault. Sequence B was composed of the highstand systems tract partially preserved around the Yokji island, lowstand systems tract mainly preserved in the Korea Trough and transgressive systems tract. After the stop of the tilting, the force of compression due to the closing of the Ulleung Basin may be released by the strike-slip faults instead of tilting.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.228-235
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• 2004

The development and proliferation of the mandibular condyle can be altered by changes in the biomechanical environment of the temporomandibular joint. The biomechanical loads were varied by feeding diets of different consistencies. The purpose of the present study was to determine whether changes of masticatory forces by feeding a soft diet can alter the trabecular bone morphology of the growing mouse mandibular condyle, by means of micro-computed tomography. Thirty-six female, 21 days old, C57BL/6 mice were randomly divided into two groups. Mice in the hard-diet control group were fed standard hard rodent pellets for 8 weeks. The soft-diet group mice were given soft ground diets for 8 weeks and their lower incisors were shortened by cutting with a wire cutter twice a week to reduce incision. After 8 weeks all animals were killed after they were weighed. Following sacrifice, the right mandibular condyle was removed. High spatial resolution tomography was done with a Skyscan Micro-CT 1072. Cross-sections were scanned and three-dimensional images were reconstructed from 2D sections. Morphometric and nonmetric parameters such as bone volume(BV), bone surface(BS), total volume(TV), bone volume fraction(BV/TV), surface to volume ratio(BS/BV), trabecular thickness(Tb. Th.), structure model index(SMI) and degree of anisotropy(DA) were directly determined by means of the software package at the micro-CT system. From directly determined indices the trabecular number(Tb. N.) and trabecular separation(Tb. Sp.) were calculated according to parallel plate model of Parfitt et al.. After micro-tomographic imaging, the samples were decalcified, dehydrated, embedded and sectioned for histological observation. The results were as follow: 1. The bone volume fraction, trabecular thickness(Tb. Th.) and trabecular number(Tb. N.) were significantly decreased in the soft-diet group compared with that of the control group (p<0.05). 2. The trabecular separation(Tb. Sp.) was significantly increased in the soft-diet group(p<0.05). 3. There was no significant differences in the surface to volume ratio(BS/BV), structure model index(SMI) and degree of anisotropy(DA) between the soft-diet group and hard-diet control group (p>0.05). 4. Histological sections showed that the thickness of the proliferative layer and total cartilage thickness were significantly reduced in the soft-diet group.

• Journal of the Korean Magnetics Society
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• v.19 no.5
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• pp.165-170
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• 2009

It is well-known that a meta-stable fcc bulk Fe has an antiferromagnetic (AFM) ground state and could be synthesized by growing Fe on a proper fcc metal substrate. In this study magnetism of Fe monolayers on nonmagnetic fcc transition metal (Cu, Rh, Pd, and Ag) (001) surfaces has been investigated using the all-electron full-potential linearized augmented plane wave method. The Fe monolayers on Rh(001) and Pd(001) surfaces were calculated to be stabilized in an AFM state, whereas the Fe monlayers on Cu(001) and Ag(001) surfaces are stabilized in a ferromagnetic (FM) state. Noting that Cu and Ag have the smallest and largest lattice constants and the fcc bulk Fe with a larger lattice constant is getting stabilized in a ferromagnetic state, it is unexpectable and interesting. The calculated magnetic moments of the Fe atoms on Cu, Rh, Pd, and Ag(001) surfaces are 2.811, 2.945, 2.987, and 2.990 $_{{\mu}B}$ in FM states and 2.624, 2.879, 2.922, and 3.001 $_{{\mu}B}$ in AFM states.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.125-125
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• 2012

물리증착(physical vapor deposition; PVD)은 진공 또는 특정 가스 분위기에서 고상의 물질을 기화시켜 기판에 피막을 형성하는 방법으로 증발과 스퍼터링 그리고 이온플레이팅 등이 있다. PVD 방법으로 박막을 제작하면 대부분의 박막은 주상정 구조로 성장하게 된다. 이러한 주상정의 조직을 제어하는 방법으로 빗각 증착(oblique angle deposition; OAD) 기술이 있다. OAD는 타겟(증발원)에 대해서 기판을 평행하게 배치하는 일반적인 코팅방법과는 달리 기판의 수직성분과 타겟의 수직성분이 이루는 각도가 0도 이상이 되도록 조절하여 기판을 기울인 상태로 코팅하는 방법을 말한다. OAD 방법을 이용하면 기판으로 입사하는 증기가 초기에 생성된 핵(seed)에 의해 shadowing이 발생하면서 증기가 수직으로 입사하는 normal 증착과는 다른 형상의 성장 조직이 만들어지게 된다. 본 논문에서는 OAD 방법을 이용하여 Al과 TiN 박막을 제조하고 그 특성을 비교하였다. Al 박막은 UBM (Un-Balanced Magnetron) 스퍼터링 소스를 이용하여 빗각을 각각 0, 30, 45, 60 및 90도의 각도에서 강판 및 실리콘 웨이퍼 상에 시편을 제조하되 단층 및 다층으로 시편을 제조하고 치밀도와 함께 조도와 반사율을 비교하고 염수분무시험을 이용하여 내식성을 평가하였다. TiN 박막은 Cathodic Arc 방식을 이용하되 Al 박막과 동일한 방법으로 코팅을 하고 내식성 및 경도 등의 특성을 비교하였다. TiN 박막은 경사각이 커지면서 경도가 낮아졌으나 바이어스 전압을 이용하여 다층으로 제조함에 의해 경도는 유지하면서 modulus를 낮출 수 있어서 박막의 신뢰성을 나타내는 H3/E2 값은 증가함을 알 수 있었다.

• Tuberculosis and Respiratory Diseases
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• v.66 no.1
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• pp.20-26
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• 2009

Background: $^{18}F$-Fluorodeoxyglucose positron emission tomography (FDG-PET) is widely used for the diagnosis and staging of non-small cell lung cancer (NSCLC). The aim of this study is to determine whether the bone marrow hypermetabolism seen on FDG-PET predicts a response to chemotherapy in patients with NSCLC. Methods: We evaluated the patients with advanced NSCLC and who were treated with combination chemotherapy. For determination of the standardized uptake value (SUV) of the bone marrow (BM SUV) on FDG-PET, regions of interest (ROIs) were manually drawn over the lumbar vertebrae (L1, 2, 3). ROIs were also drawn on a homogenous transaxial slice of the liver to obtain the bone marrow/ liver SUV ratio (BM/L SUV ratio). The response to chemotherapy was evaluated according to the Response Evaluation Criteria in Solid Tumor (RECIST) criteria after three cycles of chemotherapy. Results: Fifty-nine NSCLC patients were included in the study. Multivariate analysis was performed using a logistic regression model. The BM SUV and the BM/L SUV ratio on FDG-PET were not associated with a response to chemotherapy in NSCLC patients (p=0.142 and 0.978, respectively). Conclusion: The bone marrow hypermetabolism seen on FDG-PET can not predict a response to chemotherapy in NSCLC patients.

• Journal of the Korean Vacuum Society
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• v.3 no.1
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• pp.45-50
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• 1994

CoCr 박막에 있어서 C축 결정배향성과 미세구조 변화에 대한 Co73Cr27 씨앗층의 영향이 조사되 었다. 기록밀도가 높고 재생전압도 높은 CoCr 수직기록매체를 개발하기 위해서는 CoCr층의 두께가 엷 으면서 결정배향성이 우수하고 결정립 크기가 적고 균일한 자성기록막 제조가 필요하다. CoCr 단층막 또는 CoCr/퍼말로이 이중막 제조에서 500$\AA$정도의 Co73Cr27 층을 씨앗층으로 만들어 줌으러써 기록층인 CoCr 박막이 $0.2mu$m의 두께에서도 천이층이 거의 없고 결정배향성이 우수한 자성막을 제조할 수 있었 다. 또한 Co73Cr27 씨앗층은 비록 결정립 크기는 증가시켰지만 기록층의 에피택시 성장에 보다 바람직 한 것으로 조사되었다.

• Korean Chemical Engineering Research
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• v.44 no.3
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• pp.243-247
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• 2006

MFI zeolite membranes were prepared on anodic alumina (Anodisc) as support. First, silicalite-1(${\approx}1.2{\mu}m$) seed crystals were attached to the surface of the support via chemical bonding, and the a- and b-axis oriented zeolite membranes could be synthesized on the support coated with the monolayer of the seed crystals by secondary growth hydrothermal synthesis. The zeolite membranes prepared were characterized using scanning electron microscope and analyzed by X-ray diffraction.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.168-169
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• 2005

실온에서 디스플레이 응용을 위하여 ICP CVD로 PET기판 위에 실리콘 산화 반사 방지막을 성장시키고, EDXA로 분석하였다. 분광 Ellipsometer, UV-V와 FTIR분광기를 이용하여 반사율을 3%이하까지 낮출 수 있다는 것을 확인하였고, SEM장비를 이용하여 표면 상태를 알아보았으며. Essential Macleod 광학디자인 프로그램을 이용한 시뮬레이션 결과와 일치함을 확인하였다. 본 연구결과를 이용하면 다층박막 대신 단층 반사방지막을 제작하여 경제적이고, 효과적인 반사방지막을 제작할 수 있다.

• Journal of Embryo Transfer
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• v.9 no.3
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• pp.255-260
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• 1994

원시생식세포(primordial germ cell; PGC)는 성성숙 이후에 기능을 갖는 생식세포의 근원이 되는 세포로서, 다능성을 갖고 있는 것으로 알려져 있다. 그러므로 chimera 및 유전자 변환동물 생산을 위해 널리 사용되어 온 배아주(embrynic stem; ES)세포를 대신할 다른 세포계라고 생각되어져 많은 연구가 진행되고 있다. 본 실험은 체외배양을 통하여 원시생식세포의 증식과 확립을 위해 배양조건을 구명하고, 또한 성장인자의 효과를 검증하기 위하여 실시되었다. 원시생식세포는 12.5일째의 ICR 생쥐태아의 원시생식선 융기조직으로부터 추출하였으며, DMEM + 20% FCS + nucleosides + antibiotics로 조성된 sDMEM 배양액을 사용하여 mitomycin C로 전처리한 되먹임세포단층(feeder layer)위에서 체외배양하였다. bFGF 및 LIF를 20, 40ng/ml농도로 각각 또는 함께 첨가하여 성장인자의 효과를 검토하였다. 원시생식세포는 성에 따라 유의적인 colony 형성율을 보였고(♂:1.9 colonies / genital ridge, ♀:1.3 colonies / genital ridge), bFGF 및 LIF의 첨가 및 첨가농도에 따라서도 유의성 있는 결과를 보였다(0.3~1.9 colonies / genital riege). 그러나 3회 이상 계대배양을 할 경우, 원시생식세포의 colony를 4% prarformaldehyde로 20분간 고정한 후, tris-maleate buffer(pH 9.0)로 10분간 3회 세정하였다. Fast Red로 염색을 실시한 결과, 대부분의 colony가 염색반응을 보여 다능성을 갖는 원시생식세포의 colony임이 입증되었다. 그러나 대부분의 colony가 3회 이상의 계대배양시 생종율이 급격히 떨어지는 것을 감안하면, 또 다른 미지의 성장인자나 보다 적절한 배양조건이 요구된다고 생각된다.